Electrophotographic developers are a dry developer in which toner components composed of materials containing a colorant and a resin binder are used in a dry state, and a liquid developer in which toner components are dispersed in an insulating carrier liquid.
Since the demands for speeding up liquid developers have been more increasing, the liquid developers have also been desired to have lowered viscosities. In other words, liquid developers in which toner particles are stably dispersed in smaller particle sizes and lowered viscosities have been desired. In addition, in order to speed up, a toner which is melt-fusible in a smaller heating unit, i.e. a toner having excellent low-temperature fusing ability has been desired.
Patent Publication 1 discloses a liquid developer containing a polymeric dispersant prepared by polymerizing an ethylenically unsaturated monomer having an amino group, and an ethylenically unsaturated monomer containing an alkyl group having from 4 to 24 carbon atoms, and a plasticizer, for the purposes of obtaining excellent fusing ability, offset resistance, color developing ability, and color reproducibility, and stable optical density.
Patent Publication 2 discloses a liquid developer containing a polymeric dispersant prepared by polymerizing an ethylenically unsaturated monomer having an amino group, and an ethylenically unsaturated monomer containing an alkyl group having from 9 to 24 carbon atoms, for the purposes of obtaining excellent color developing ability and color reproducibility, and stable dispersion state and optical density of the toner particles.
Patent Publication 1: Japanese Patent Laid-Open No. 2014-092579
Patent Publication 2: Japanese Patent Laid-Open No. 2014-132324